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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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612762e82a
This patch adds DMA capabilities to the spi-qup driver. If DMA channels are present, the QUP will use DMA instead of block mode for transfers to/from SPI peripherals for transactions larger than the length of a block. Signed-off-by: Andy Gross <agross@codeaurora.org> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org> Reviewed-by: Ivan T. Ivanov <iivanov@mm-sol.com Signed-off-by: Mark Brown <broonie@kernel.org>
104 lines
3.1 KiB
Plaintext
104 lines
3.1 KiB
Plaintext
Qualcomm Universal Peripheral (QUP) Serial Peripheral Interface (SPI)
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The QUP core is an AHB slave that provides a common data path (an output FIFO
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and an input FIFO) for serial peripheral interface (SPI) mini-core.
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SPI in master mode supports up to 50MHz, up to four chip selects, programmable
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data path from 4 bits to 32 bits and numerous protocol variants.
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Required properties:
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- compatible: Should contain:
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"qcom,spi-qup-v1.1.1" for 8660, 8960 and 8064.
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"qcom,spi-qup-v2.1.1" for 8974 and later
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"qcom,spi-qup-v2.2.1" for 8974 v2 and later.
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- reg: Should contain base register location and length
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- interrupts: Interrupt number used by this controller
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- clocks: Should contain the core clock and the AHB clock.
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- clock-names: Should be "core" for the core clock and "iface" for the
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AHB clock.
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- #address-cells: Number of cells required to define a chip select
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address on the SPI bus. Should be set to 1.
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- #size-cells: Should be zero.
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Optional properties:
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- spi-max-frequency: Specifies maximum SPI clock frequency,
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Units - Hz. Definition as per
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Documentation/devicetree/bindings/spi/spi-bus.txt
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- num-cs: total number of chipselects
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- cs-gpios: should specify GPIOs used for chipselects.
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The gpios will be referred to as reg = <index> in the SPI child
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nodes. If unspecified, a single SPI device without a chip
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select can be used.
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- dmas: Two DMA channel specifiers following the convention outlined
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in bindings/dma/dma.txt
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- dma-names: Names for the dma channels, if present. There must be at
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least one channel named "tx" for transmit and named "rx" for
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receive.
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SPI slave nodes must be children of the SPI master node and can contain
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properties described in Documentation/devicetree/bindings/spi/spi-bus.txt
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Example:
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spi_8: spi@f9964000 { /* BLSP2 QUP2 */
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compatible = "qcom,spi-qup-v2";
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#address-cells = <1>;
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#size-cells = <0>;
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reg = <0xf9964000 0x1000>;
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interrupts = <0 102 0>;
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spi-max-frequency = <19200000>;
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clocks = <&gcc GCC_BLSP2_QUP2_SPI_APPS_CLK>, <&gcc GCC_BLSP2_AHB_CLK>;
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clock-names = "core", "iface";
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dmas = <&blsp1_bam 13>, <&blsp1_bam 12>;
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dma-names = "rx", "tx";
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pinctrl-names = "default";
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pinctrl-0 = <&spi8_default>;
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device@0 {
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compatible = "arm,pl022-dummy";
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#address-cells = <1>;
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#size-cells = <1>;
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reg = <0>; /* Chip select 0 */
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spi-max-frequency = <19200000>;
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spi-cpol;
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};
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device@1 {
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compatible = "arm,pl022-dummy";
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#address-cells = <1>;
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#size-cells = <1>;
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reg = <1>; /* Chip select 1 */
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spi-max-frequency = <9600000>;
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spi-cpha;
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};
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device@2 {
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compatible = "arm,pl022-dummy";
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#address-cells = <1>;
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#size-cells = <1>;
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reg = <2>; /* Chip select 2 */
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spi-max-frequency = <19200000>;
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spi-cpol;
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spi-cpha;
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};
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device@3 {
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compatible = "arm,pl022-dummy";
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#address-cells = <1>;
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#size-cells = <1>;
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reg = <3>; /* Chip select 3 */
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spi-max-frequency = <19200000>;
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spi-cpol;
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spi-cpha;
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spi-cs-high;
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};
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};
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